There's a moment at the bottom of every long climb where your brain lies to you. The gradient kicks up, riders around you accelerate, and something primal fires: you need to go with them. You need to respond. You need to prove you belong.
So you push 280 watts when your plan says 250. It feels fine for 90 seconds. Then the elastic snaps. By minute four, you're grinding at 220 and watching the riders who started sensibly cruise past in a rhythm you've already lost.
This happens to nearly every amateur cyclist, and it happens for a specific physiological reason.
Why the First 2 Minutes Lie
When you suddenly increase power output at the base of a climb, your aerobic system doesn't respond instantly. There's a delay — the oxygen kinetics lag — and during that lag, your anaerobic system picks up the slack. It feels sustainable because you're running on a credit card. But the bill comes due within 2-3 minutes.
That burst at the bottom generates lactate faster than your body can clear it. By minute three, your blood lactate concentration has spiked, your breathing is ragged, and you're forced to drop power significantly below your sustainable threshold to recover. You've effectively turned a 20-minute steady effort into a 20-minute survival exercise.
Prof Andrew Jones from the University of Exeter has published extensively on oxygen uptake kinetics and pacing. The research consistently shows that even starts or slight negative splits produce better outcomes than fast starts for efforts lasting 10 minutes or longer.
The Negative Split Approach
Negative splitting means riding the second half of a climb faster than the first. Not dramatically faster — just a few watts. The principle is restraint early, effort late.
Sir Bradley Wiggins described his time trial approach — which applies perfectly to climbing — as riding the course, not the competition. Ignore what others do around you. Execute your plan.
Here's how it works in practice:
First quarter of the climb: 90-95% of your target average power. This is the restraint phase. Your RPE should be around 6-7/10. It should feel too easy. That's the point.
Middle half: Settle at your target power. RPE 7-8/10. Find a rhythm — cadence, breathing, position on the bike. This is where the climb happens.
Final quarter: This is where you spend whatever's left. Push to 105-110% of target. RPE 9-10/10. You've earned the right to suffer now, and you have the physiological headroom to do it because you didn't burn it at the bottom.
Power Targets by Climb Duration
The power you can sustain depends on how long the effort lasts. These are approximate targets based on FTP for a well-paced effort:
10-minute climb: Target 105-108% of FTP. This sits at the top of your VO2max range. Start at 100% FTP, settle at 106%, push to 115% in the final 2 minutes.
20-minute climb: Target 95-100% of FTP. This is threshold territory. Start at 90% FTP, hold 97% through the middle, push to 105% for the final 4 minutes.
30-minute climb: Target 88-93% of FTP. You're now below threshold, in sweet spot territory. Start at 85% FTP, hold 90% for the middle 20 minutes, push to 100% for the final 5 minutes.
45 minutes and beyond: Target 80-88% of FTP. Patience becomes everything. The margins between "controlled" and "blown up" narrow. Start conservative and stay there for 30 minutes before you even consider pushing.
These targets assume you're pacing a single effort, not racing in a group where tactics dictate tempo changes. If you want to see how a specific climb plays out at your power numbers, the Race Predictor will model your split times based on gradient profile, body weight, and sustainable power.
Power-Based vs RPE-Based Pacing
If you have a power meter, use it as a ceiling in the first half and as a floor in the second half. The first half is about not going over. The second half is about pushing up to whatever's left.
But power alone has limits. A power meter can't tell you how you feel. It can't tell you whether today is a 95% day or a 100% day. RPE fills that gap.
The combination looks like this:
- First quarter: Check power is under 95% target. RPE should confirm — 6-7/10. If RPE is already 8/10 at 95% power, you're having a bad day. Adjust the target down.
- Middle half: Hold power at target. RPE should be 7-8/10. If it's creeping to 9/10, ease off 3-5 watts.
- Final quarter: RPE 9-10/10. Let power be whatever it is. Finish empty.
If you don't have a power meter, RPE is your primary tool. The rule is simpler: if you're breathing hard in the first 3 minutes, you're going too hard. The first quarter should feel like you're holding yourself back. Because you are.
Cadence on Long Climbs
Most riders default to grinding a big gear on climbs because it feels powerful. Research from Lucia et al. studying professional climbers found they typically maintained cadence between 70-90 rpm on sustained climbs, varying based on gradient and personal preference.
For most amateurs, 75-85 rpm is the productive range on climbs. Below 70, the muscular cost per revolution increases and your quads fatigue faster. Above 90, the cardiovascular cost increases. Find the cadence where you can sustain target power without either your legs or your lungs being the limiter.
A useful drill: on your next long climb, spend 5 minutes in a gear 2-3 teeth easier than your default. Notice what happens. Your heart rate might rise slightly, but your legs will feel fresher at the top. That's often the better trade.
Pre-Ride the Climb (Mentally)
If you know the climb profile — and you should before any event — break it into sections. Where does the gradient ease? Where does it kick up? Where's the false flat where you can soft-pedal and recover?
That mental map prevents reactive pacing. Without it, every gradient change is a surprise and you're constantly adjusting power. With it, you know the steep section at kilometre 4 is only 800 metres long, so you can sit in and spin instead of panicking.
The Race Predictor will break any climb into gradient segments and model your pace through each one. Pair that with the negative split framework above and you walk into the event with a plan that accounts for the terrain, not just a flat-road power target.
Key Takeaways
- The first 2 minutes of a climb feel deceptively easy because your anaerobic system masks the effort
- Negative split pacing (second half faster than first) produces faster overall times than positive splitting
- Start at 90-95% of target power, settle at target, push to 105-110% in the final quarter
- Use power as a ceiling in the first half and RPE as your guide in the second half
- Cadence of 75-85 rpm balances muscular and cardiovascular cost on sustained climbs
- Study the gradient profile before the event and pace each section, not just the climb as a whole
If your climbing has stalled despite consistent training, the limiter might not be pacing at all — it could be threshold power, body composition, or fuelling. The Plateau Diagnostic identifies which factor is holding you back. Four minutes, free.